U.S. stocks were largely flat in thin, holiday-shortened trading on Wednesday, December 24, 2025, with investors watching whether the market can extend a year-end “Santa Claus rally” even as headlines moved individual names sharply. The S&P 500 hovered near its all-time highs after a record close the prior session, while standout moves centered on three widely followed companies: Intel, Nike, and Dynavax Technologies. [1]
Intel’s shares fell after a report said Nvidia halted a test of Intel’s next-generation 18A manufacturing process, a development that reignited investor concerns about Intel’s effort to become a major contract chipmaker. Nike climbed after Apple CEO Tim Cook disclosed a roughly $3 million open-market purchase of Nike shares, a rare insider-style vote of confidence amid a difficult turnaround. And Dynavax surged after Sanofi agreed to buy the vaccine maker for about $2.2 billion, adding an approved hepatitis B vaccine and a shingles candidate to Sanofi’s pipeline at a moment of heightened uncertainty for U.S. vaccination policy. [2]
Below is what’s driving the moves—and why these stories matter beyond Christmas Eve’s quiet tape.
Intel stock drops after Nvidia halts testing of the 18A process
What happened
Intel shares slid after reporting indicated Nvidia tested Intel’s 18A process but “stopped moving forward”—a phrase markets interpreted as a setback for Intel’s push to prove that 18A can attract elite external customers. Intel’s stock was down roughly 2% in early action in several reports, after falling as much as 3.9% at the open before paring losses. [3]
Intel told Reuters, through a spokesperson, that its 18A manufacturing technologies are “progressing well.” Nvidia did not respond to a request for comment in the reporting cited across multiple outlets. [4]
Why 18A matters to Intel’s turnaround
For Intel, 18A isn’t just another manufacturing node—it’s central to the company’s plan to restore leadership in advanced chipmaking and build a credible Intel Foundry business that can compete with Taiwan Semiconductor Manufacturing Co. (TSMC).
Intel has been positioning 18A as a “make-or-break” technology for two reasons:
- Internal competitiveness: 18A is designed to bring Intel’s own high-end chips back onto its most advanced in-house process, narrowing gaps with rivals.
- External credibility: Landing a marquee customer—especially an AI powerhouse—would validate Intel as a serious alternative to TSMC for cutting-edge production.
That second point is why the Nvidia testing story hit the stock so quickly: if the world’s most influential AI-chip designer isn’t ready to proceed, investors worry other prospective customers could hesitate too.
What Intel says 18A changes technologically
Intel has marketed 18A as a major architectural step, incorporating two marquee innovations highlighted in coverage of the report:
- Gate-all-around (GAA) transistors: A transistor structure designed to improve control and efficiency as chips pack in more devices.
- A new approach to power delivery (often described as backside power): Intended to improve efficiency and scaling by changing how power is delivered through the chip structure.
These features are widely seen as key levers for improving performance-per-watt—an especially critical metric for AI and data-center chips. [5]
The broader context: Nvidia’s investment, but no manufacturing commitment
The timing is particularly notable because Intel and Nvidia are already tied together by a high-profile partnership announced in September 2025, which included Nvidia’s commitment to invest $5 billion in Intel stock (at a purchase price cited as $23.28 per share in one report), alongside plans to collaborate on custom x86 CPUs and PC system-on-chips integrating Nvidia GPU chiplets. [6]
But crucially, multiple reports emphasize that the partnership did not include a commitment for Intel to manufacture Nvidia’s chips—leaving open the possibility that Nvidia could remain a collaborator and shareholder without becoming a foundry customer. [7]
That distinction is now at the center of the market’s debate: is Nvidia’s testing pause a temporary step in a long qualification process, or an early signal that Intel Foundry still has work to do before it can win the most demanding workloads?
Intel’s political and strategic tailwinds—and the lingering execution question
On the same day as the market reacted to the Nvidia testing headline, Reuters published a deeper look at Intel CEO Lip-Bu Tan and the political and strategic dynamics shaping Intel’s future—including a U.S. government investment that resulted in the government taking a roughly 10% stake in Intel, and how that “too strategic to fail” aura could open doors with partners. The report also notes Intel’s manufacturing unit has “struggled to produce quality in-house chips” even as deal momentum improved. [8]
For investors, that combination—strong strategic backing, plus hard manufacturing realities—is exactly why a story about 18A testing can move the stock so sharply.
What to watch next for Intel
Key questions heading into the final days of 2025 and early 2026:
- Customer pipeline: Whether Intel can confirm meaningful foundry progress with other large chip designers.
- 18A ramp and yields: How quickly Intel can scale 18A production and demonstrate consistent quality.
- Next-node interest (14A): Intel has said it continues to see “strong interest” in its next-generation 14A process. [9]
Nike stock rises after Tim Cook’s $3 million purchase signals confidence
The headline move
Nike shares rose after a regulatory filing showed Apple CEO Tim Cook bought 50,000 Nike shares at $58.97 each, an open-market purchase worth about $3 million. Cook has been on Nike’s board since 2005 and has served as lead independent director since 2016. After the purchase, Cook held about 105,000 shares, worth nearly $6 million at the time cited in reports. [10]
Reuters reported Nike shares were up about 5% in early trading following the disclosure. [11]
Why the market cared: “insider-style” buying during a bruising turnaround
Big open-market buys by high-profile directors and executives tend to stand out because they are comparatively rare—and because investors often read them as a personal conviction signal.
In Nike’s case, the buy arrives at a sensitive moment:
- Nike recently reported results showing weaker margins and softness in China, a major growth market where competition and pricing pressure remain intense. [12]
- CEO Elliott Hill is executing a turnaround that includes refreshed marketing, product innovation (especially in running and sport), and rebuilding relationships with wholesalers to improve visibility at retail. [13]
- Those initiatives, however, can squeeze margins in the short run—exactly what Nike has been grappling with. [14]
A Baird analyst quoted by Reuters described Cook’s move as a positive signal for progress under Hill and Nike’s “Win Now” actions. Reuters also reported the purchase may be the largest open-market purchase by a Nike director or executive in more than a decade. [15]
Another notable buyer: Robert Swan
Nike also disclosed another director purchase: Robert Swan, identified in Reuters’ report as a former Intel CEO, bought roughly 8,700 shares for about $500,000. Multiple director buys in close proximity can amplify the “confidence” narrative, even if the business challenges remain. [16]
What to watch next for Nike
Investors will be monitoring:
- China demand trends and the effectiveness of Nike’s strategy to win back momentum.
- Margin trajectory as Nike balances innovation, marketing, and channel strategy.
- Wholesale and distribution execution, including how improved retailer relationships translate into sell-through.
Dynavax surges as Sanofi agrees to $2.2 billion acquisition
Deal terms and immediate market reaction
Dynavax shares jumped after Sanofi announced it would acquire Dynavax Technologies for about $2.2 billion, paying $15.50 per share in cash—a 39% premium to Dynavax’s prior close of $11.13. Sanofi said it expects to complete the deal in Q1 2026, using available cash, and that it does not expect the transaction to affect its 2025 financial outlook. [17]
Dynavax shares rose roughly 37% in U.S. premarket trading after the announcement in Reuters’ reporting. [18]
Why Sanofi wants Dynavax: approved hepatitis B vaccine plus shingles upside
The acquisition gives Sanofi access to Dynavax’s marketed adult hepatitis B vaccine and, importantly, to a shingles candidate:
- Reuters highlighted that the deal includes an experimental shingles vaccine (identified as Z-1018) in early-stage testing. [19]
- Bloomberg’s “Stock Movers” episode also underscored the shingles candidate and noted the Sanofi announcement came minutes after Sanofi said the FDA rejected its experimental multiple sclerosis drug tolebrutinib—a reminder that M&A can serve as a strategic counterweight when pipeline news disappoints. [20]
J.P. Morgan analysts, cited by Reuters, suggested Z-1018 could offer upside if early data holds up in larger trials, pointing to the size of the shingles market where GSK’s Shingrix remains a dominant product. [21]
A complicated backdrop: U.S. vaccination policy and falling rates
Reuters also framed the Dynavax deal against a shifting U.S. vaccine environment, noting declining vaccination rates and describing significant policy controversy involving Health Secretary Robert F. Kennedy Jr. and changes to hepatitis B recommendations for newborns. The message: Sanofi is buying a vaccine asset in a market where demand dynamics and policy signals have become more unpredictable. [22]
What to watch next for Sanofi and Dynavax
Key milestones include:
- Regulatory and closing timeline: Sanofi expects close in Q1 2026. [23]
- Commercial execution: How Sanofi integrates Dynavax’s hepatitis B franchise into its broader vaccine business.
- Pipeline progress: Whether Z-1018 generates data strong enough to justify Sanofi’s longer-term expectations.
Christmas Eve market backdrop: “Santa Claus rally” watch in thin trading
The moves in Intel, Nike, and Dynavax unfolded as the broader market traded with lighter holiday liquidity:
- Reuters reported U.S. markets were operating in a shortened session, closing at 1 p.m. ET, with Christmas Day closures to follow. [24]
- The S&P 500 hovered about 0.1% away from its intraday record after a record close the previous day. [25]
- Reuters noted hopes for a “Santa Claus rally,” a historically strong period spanning the last five trading days of the year and the first two of January—beginning December 24 and running through January 5 in 2025’s calendar setup. [26]
- Fresh U.S. data showed jobless claims unexpectedly fell, suggesting steady labor market conditions even as other indicators sent mixed signals. [27]
In that environment, single-stock catalysts—especially those tied to AI hardware, mega-cap consumer brands, and large healthcare M&A—had an outsized ability to shape headlines.
Bottom line: three stories, one theme—confidence vs. execution
Christmas Eve’s biggest stock movers delivered a clear cross-sector message:
- Intel is still in a credibility-building phase for Intel Foundry, where even a pause in customer testing can overwhelm broader strategic tailwinds. [28]
- Nike got a rare confidence boost from a prominent board member’s personal purchase, but the turnaround still hinges on improving demand and stabilizing margins. [29]
- Dynavax became the day’s clearest winner as Sanofi paid a premium for vaccine growth, signaling that large pharma remains willing to deploy cash for differentiated, near-term revenue assets with pipeline optionality. [30]
If you’d like, I can tailor this into (1) a tighter ~700-word Google Discover format with faster pacing, or (2) a longer ~1,800-word Google News feature with more background on Intel’s foundry strategy and the vaccine market dynamics—without adding any charts or images.
References
1. www.reuters.com, 2. www.investing.com, 3. www.investing.com, 4. www.investing.com, 5. www.ndtvprofit.com, 6. www.investing.com, 7. www.ndtvprofit.com, 8. www.reuters.com, 9. www.reuters.com, 10. www.reuters.com, 11. www.reuters.com, 12. www.reuters.com, 13. www.reuters.com, 14. www.reuters.com, 15. www.reuters.com, 16. www.reuters.com, 17. www.reuters.com, 18. www.reuters.com, 19. www.reuters.com, 20. www.bloomberg.com, 21. www.reuters.com, 22. www.reuters.com, 23. www.reuters.com, 24. www.reuters.com, 25. www.reuters.com, 26. www.reuters.com, 27. www.reuters.com, 28. www.reuters.com, 29. www.reuters.com, 30. www.reuters.com
